In the recent automotive industry, according as the global interest in environment and energy is increased, there has been performed research and development in the improvement of fuel efficiency. And, in order to satisfy various users' requirements, there has been also proceeded research and development in light, small and multi-functional automobiles. Also, the evaporator has been improved to realize the smaller size and to increase the heat exchange efficiency together.
The evaporator is a component of an air conditioner in which air introduced by an air blower is cooled due to heat exchange while liquid heat exchange medium is changed into a gaseous state and then the cooled air is supplied inside a vehicle.
A conventional evaporator includes first and second header tanks which forms at least one or more compartments and disposed to be parallel with each other; inlet and outlet pipes which are formed at one side of the first header tank; a baffle which is provided in the first or second header tank to control a flow of refrigerant; a core portion having a plurality of tubes of which both ends are fixedly disposed at the first and second header tanks to form a first row communicated with the inlet pipe and a second row communicated with the outlet pipe, and a plurality of fins which are interposed between the tubes; and a communication portion which has a communicating hole for communicating a part of the first and second rows.
Since the evaporator is comprised of the first and second rows, even though a flow passage of the header tank and the tube is formed properly, the flow of refrigerant is considerably changed according to a size of the communicating hole of the communication portion for communicating the first and second rows.
Further, in the evaporator, the refrigerant is flowed through the header tank and the tube, and while external air is flowed along the fin interposed between the tubes, the heat exchange is occurred between the refrigerant and the external air. Thus, if a height of the tube is high, the internal refrigerant is smoothly flowed, but since a height of the external fin is reduced and thus the flow of external air is restricted, the heat exchange performance is deteriorated. However, if the height of the tube is low, the external air can be smoothly flowed, but the flow of internal refrigerant is restricted and thus the heat exchange performance is deteriorated.
A surface temperature of the evaporator is changed according to the size and surface area of the communicating hole, and the height of the fin and tube, and temperature deviation on a surface of the core portion may be occurred.
However, in the conventional evaporator, there was provided only limitation of its shape or general dimensions, and there was never provided a detailed dimensional extent such as the surface area of the communicating hole and the number of the communicating holes considering the flow of refrigerant, and the height and the surface area of the fin and tube and a density of the fins considering a pressure drop amount of the refrigerant and the like.